Have you checked how much a 7ah battery draws from flat, its alot more than most 1.5 amp PSU,S can supply.

99% of control panels limit the current available to charging batteries to a few hundred milliamps max, and as of yet I have NEVER encountered a totally dead new battery.

Anyway a panel will slowly charge the battery over a 24hr period from dead, these gell cell batteries arent designed to be fast charged.

I sort of agree with Pete in that the likely charge current should be factored in when designing the system because the cc is part of the current draw. In practical terms though as long as all the gear connected to the panel is well within the panels spec things should be OK, and just because the spec says 1Ah output available taking a panel upto 980ma is not a good idea. Additional PSUs without a common neg to the panel can sort out loads of problems anyway.

The only panels that I have seen blow a fuse trying to charge a flat batt are optimas.

Additional PSUs without a common neg to the panel can sort out loads of problems anyway.

Dont you mean WITH a common neg mate

no I mean without!

Hmm ok correct me if im wrong here but surely you should common up the negs on any psus used to power the system

what we often do is use a PSU for all the detectors and the panel for keypads only. No need to common the neg unless you want to use latch.

Fair enough although i always common negs on psus, latch or not

theres nothing wrong with that but sometimes removing the common neg leg can solve those daft faults. Dont ask me why!

theres nothing wrong with that but sometimes removing the common neg leg can solve those daft faults. Dont ask me why!

30989[/snapback]

It could be due the automatic battery test the panel does..